Flat Earthers believe this photo of the Earthrise taken in 1968 from Apollo 8, is a fake.
Photograph: -/AFP/Getty Images

There was the three-hour presentation which contended that the universe is a giant egg. There was the Manchester musician who posited that the Earth is the shape of a diamond. And another who believes that the moon is a projection.

Welcome to the Flat Earth UK Convention, a raucous departure from scientific norms where people are free to believe literally anything.

“When people ask me what I believe, I can’t say that I believe in anything 100%”, Gary John tells the audience during his opening address. “Apart from that we don’t live on a globe”.

That unshakeable belief is one of the few points of total agreement for the 200-strong audience at this week’s gathering. There is less consensus, however, on what form the Earth actually takes: some believe it to be a disc with the Arctic circle in the middle; some believe that circle is under a dome, above which there may or may not be an expanse of water; others believe the Earth is just one in a series of ponds in a vast expanse of ice; and other still believe the Earth exists beneath four cosmic rings within a giant egg-shaped universe.

Most do not believe in space; none believe mankind has ever travelled there.

One speaker, Manchester-based musician Darren Nesbitt, dismisses the circular model of the Earth entirely, correctly critiquing that the Sun would have to travel faster in the South to make it around the outer-edge of the circle, which does not match our observations.

“You can’t just trust YouTube”, he implores the audience during his talk, “you have to be your own authority”.

The Earth, according to Nesbitt, is more likely a diamond shape, with East-West travel facilitated by 4D space-time warps along the edges, allowing for a “Pac-Man” version of reality – where a traveller might sail off one side of the screen, and appear at the other side. That diamond is propped up on seven circular pillars, “because God likes the number seven”. This version, he explains, fits the evidence better, and is supported by the Bible, in the book of Job.

Several speakers throughout the weekend take time to highlight that evolution is a myth, accompanied by occasional heckles of “monkey men!” from audience members.

To their credit, there are members of the Flat Earth community who are determined to disprove the globe model through scientific experiments: some use high-powered lasers over bodies of water to try to attempt to observe any curvature, others creating complex 3D models to explain the movements of the Sun and stars.

Although the ideas have persisted for generations, the modern Flat Earth phenomena is surprisingly recent. When I first encountered the community in 2013, Flat Earth arguments played out on a fringe messageboard, with some dispute over whether proponents actually believed in the theories they espoused or whether they simply enjoyed the intellectual pursuit of arguing an untenable position. However, if there were disbelievers among the 200 attendees at the conference, they were exceptionally convincing; there seems little doubt over the sincerity of modern Flat Earth proponents.

Almost all of the speakers came to the Flat Earth within the last five years: Nesbitt “came out” as a Flat Earther in 2015; Gary John found the movement in August 2015; Martin Liedtke in 2015. Almost all – speakers and attendees alike – credit their conversion to the Flat Earth to YouTube, watching videos like those produced by American Flat Earth star Mark Sargent.

Fame in the Flat Earth world is not without its pitfalls, however, as Sargent’s standing in the UK movement demonstrates. Sargent was booked to speak at the conference, before he gave interviews to the BBC and Good Morning Britain, in which he espoused his belief that the Earth exists under a dome, like a snowglobe. These interviews reflected badly on the community, Gary explained to me during lunch, so he contacted Sargent to air his concerns over the interviews, and how they were perceived by members of the Flat Earth community. In response, Sargent publicly and acrimoniously withdrew from the conference.

“It shows the height of the planes as they fly”, he told me, excitedly. “If the Earth was round, we’d see their heights all change as they fly over the curve!”

“Isn’t it measuring altitude?” I asked, “So that’s the elevation above the ground. If the ground curved, and the plane’s path naturally curved with it, it would stay the same distance from the ground – which is exactly what we see in that video, don’t we?”

He paused for a moment.

“That’s interesting”, he said, “I’ll have to think about that”.

Dave Marsh, an NHS manager from Derbyshire who came to Flat Earth belief in November 2016, tracked the movement of the moon across the night sky, in order to compare his observations to the “official” records and see if the movement of the moon matched that of the ‘Globalist’ model. The results of his backyard experiment differed from data he found online, leading him to conclude that “the moon is a projection, put there for a reason, which we could study for a thousand more years and never understand”. A more cautious experimenter might look to the accuracy of their equipment before drawing so radical a conclusion, but it’s hard not to admire his commitment.

Other speakers focus not on experimentation, but on observation and “common sense”. Dave Murphy, something of a celebrity in the Flat Earth movement after appearing on Macedonian TV in 2016, dedicated his talk to “debunking the debunkers” – bombastically dismissing arguments from Globalist physicists like Neil Degrasse Tyson. It was hard not to be charmed by Dave’s confidence and charisma as he took us through some of his refutations of the criticisms levelled at his theories, even if his understanding of distance, scale, and the movement of bodies in a closed system left a lot to be desired.

Interestingly, when it came to debunking some of the theories put forward by Flat Earth proponents – including the “transparent moon” theory and the false notion that photographs can show clouds passing behind the Sun – Dave’s delivery shifted completely. Gone was his confident swagger as he poked holes in theories the audience might hold dear. Flat Earth belief may be a broad church, but they are not above turning on their own.

The reluctance to submit their own theories to the level of scrutiny comes as little surprise, though it remains no less disappointing to witness. While the conference did include a debate with physics PhD candidates from Imperial College London and Cardiff University (who spoke with calmness and good-natured warmth in the face of exceptional pressure), self-examination was in short supply.

In fact, one of the most telling moments of the weekend came in Darren Nesbitt’s talk, after he dismissed the disk Earth as being “counter-intelligence” set out to throw people off the scent, and before he explained that the Earth is a diamond, resting on seven circular pillars, operating in a 4D Pac-Man version of reality.

Nesbitt shared what he called the “Flat Earth Addiction” test – seven questions Flat Earth proponents should ask themselves, including “Have people said that you are pushy or obsessive about Flat Earth?”, “Have you thought that if only everyone knew about Flat Earth the world would be a different place?”, and “Have you noticed that you spend less and less time with your family and friends and more and more time talking to Flat Earthers?”.